Thursday, October 18, 2012

KT and the Extinction Event

Its always a bad idea to ascribe a single cause for any historical event. Its easy to say that World War I was caused when the Arch-Duke Franz Ferdinand was killed in Sarajevo, but that was no more the cause of World War I than Caesar's ego was the cause of the fall of the Roman Republic.

The KT extinction event, that moment that the dinosaurs were wiped off the face of the earth suffers a similar problem. Its hard to imagine this one event, the meteor touch down, wiping out all the terrible lizards in one giant fireball. But that's what we are led to believe.

That should and is questioned. The layer of sediment caused by the meteor is very thin, and marked at about 65 million years ago. However, dinosaur bones have been found in sediment after the event; 700,000 years after the event.

Its also interesting to me how insanely quickly volcano ash is cleaned from the atmosphere. We like to imagine such an event as the meteor would make Venus-like atmospheric conditions (remember the Nuclear Winter of the 80s?); but I wonder about this. Krakatoa exploded in 1883, creating an explosion equal to about 13000 atomic bombs and one heard 3000 miles away. Within 5 years everything in the region had settled back to normal.

Science should always avoid the extremes. Eco-systems are not fragile, they are constantly evolving.

I suspect the meteor hit, caused wide spread devastation but many of the terrible lizards survived to carry on for another million or plus years. These mass extinctions are probably slow, staggered affairs.

I love that line from Jurassic Park: Life will find a way.

That meteor certainly doesn't explain the Triassic mass extinction or the late Devonian mass extinction.

What causes these? I can't say for sure, but we might all want to get that corrugated bunker from the previous article, our number may be up!